Burrowing pests have been a problem for gardeners, ranchers, and farmers since time in immemorial. There have been many devices for the specific purpose of combating burrowing pests in their underground burrows including spring traps, jaw traps, spring spears, steel traps, poisons, and explosive devices. Eradicating burrowing pests is made more difficult because the pest burrow may be quite long with various entry points, underground chambers, and various escape routes. Poisonous gases have been utilized but this is dangerous to the operator and may involve such environmental impact as to make it impractical.
Explosive gases have also been injected into the system of burrows of burrowing animals. The use of explosive gases can be effective, but faces certain challenges. An applicator for injecting flammable gases into an underground burrow must cause the gas to penetrate deeply into the system of burrows for it to be effective. Usually, the flammable gas is a mixture of oxygen and a flammable gas and, at a certain distance from the injection point, the two gases can separate and the effectiveness of the combustion may become greatly reduced. Such a device also has to be very safe for the applicator so that there is no possibility of combustion around the applicator or of carrying the combustion into the device itself.